Eretz Tzvi - The Expanding Land
The comparison of Eretz Yisrael to the skin of a deer which one Talmudic Sage interpreted as a tribute to the lands ability to produce fruits quickly and plentifully was applied by Rabbi Chanina to the expanding nature of its territory.
Challenged by a heathen skeptic how it was possible, as the Sages claimed, that millions of Jews once lived in a part of Eretz Yisrael called Har Hamelech, he referred him to the Prophet Yirmiyahu’s description of the country as "the land of the deer". Just as when the skin of a deer is removed from its carcass it is impossible to once again have it envelop the animal’s flesh because of its contraction, so too when Jews live in Eretz Yisrael the land expands to absorb them after contracting when they are not there.